path: root/rpc/codec/json.go

package codec

import (
    "encoding/json"
    "net"

    "github.com/ethereum/go-ethereum/rpc/shared"
)

const (
    MAX_RESPONSE_SIZE = 64 * 1024
)

// Json serialization support
type JsonCodec struct {
    c net.Conn
    d *json.Decoder
    e *json.Encoder
}

// Create new JSON coder instance
func NewJsonCoder(conn net.Conn) ApiCoder {
    return &JsonCodec{
        c: conn,
        d: json.NewDecoder(conn),
        e: json.NewEncoder(conn),
    }
}

// Serialize obj to JSON and write it to conn
func (self *JsonCodec) ReadRequest() (*shared.Request, error) {
    req := shared.Request{}
    err := self.d.Decode(&req)
    if err == nil {
        return &req, nil
    }
    return nil, err
}

func (self *JsonCodec) ReadResponse() (interface{}, error) {
    var err error
    buf := make([]byte, MAX_RESPONSE_SIZE)
    n, _ := self.c.Read(buf)

    var failure shared.ErrorResponse
    if err = json.Unmarshal(buf[:n], &failure); err == nil && failure.Error != nil {
        return failure, nil
    }

    var success shared.SuccessResponse
    if err = json.Unmarshal(buf[:n], &success); err == nil {
        return success, nil
    }

    return nil, err
}

// Encode response to encoded form in underlying stream
func (self *JsonCodec) Decode(data []byte, msg interface{}) error {
    return json.Unmarshal(data, msg)
}

func (self *JsonCodec) Encode(msg interface{}) ([]byte, error) {
    return json.Marshal(msg)
}

// Parse JSON data from conn to obj
func (self *JsonCodec) WriteResponse(res interface{}) error {
    return self.e.Encode(&res)
}

// Close decoder and encoder
func (self *JsonCodec) Close() {
    self.c.Close()
}